Printer control logic

Abstract

There is disclosed herein printer control logic for controlling a matrix printer. The control logic includes an interruptable microprocessor, together with associated memory. Additionally the control logic includes a programmable timer which provides a signal a determined time after being programmed. The control logic responds to print emitter signals manifesting an incremental movement of the print head by interrupting the microprocessor. The microprocessor then programs the timer to provide signals after a programmed delay time to again interrupt the microprocessor. The microprocessor then provides signals causing the operation of the print elements on print head.

What is claimed is: 
     
       1. Control means for a printer having a matrix print head which bidirectionally moves across a record medium, said print head printing information on said medium by selective operation of the print elements of said print head, said control means comprising: means for providing position signal sequences at periodic interim positions as said print head moves across said medium, the sequence of said position signals manifesting the direction said print head moves;   interruptable processor means responsive to an interrupt signal for being interrupted to provide a first control signal to selectively operate said print elements after being interrupted and to further provide a second control signal in response to said position signal sequence; and   decoding means responsive to said position signals and said second control signal for providing said interrupt signal each time said position signal indicates said print head has reached a different interim position.   
     
     
       2. The invention according to claim 1 wherein said position signal providing means includes printer emitter means for providing a signal which changes in a defined manner based upon the direction said print head moves in response to specific interval movement of said print head. 
     
     
       3. The invention according to claim 2 wherein said position signal providing means further includes means responsive to said emitter means signal for providing an interrupt signal to said processor means each time said emitter means signal changes. 
     
     
       4. Control means for a printer having a matrix print head which moves across a record medium, said print head printing information on said medium by selective operation of the print elements of said print head, said control means comprising; means for providing position signals at periodic interim positions as said print head moves across said medium;   interruptable processor means responsive to said position signals for being interrupted to provide a control signal to selectively operate said print elements after being interrupted;   wherein said position signal providing means includes printer emitter means for providing a signal which changes in response to specific interval movement of said print head;   wherein said position signal providing means further includes means responsive to said emitter means signal for providing an interrupt signal to said processor means each time said emitter means signal changes;   wherein said means for providing said interrupt signal further responds to a second control signal from said processor means; and   wherein said means for providing said interrupt signal includes exclusive OR means responsive to said emitter means signal and to said second control signal, said interrupt signal being provided by said exclusive OR means whenever said emitter means signal changes, said processor means further responding to said interrupt signal to cause a corresponding change in said second control signal so that subsequent interrupt signals are provided by said exclusive OR means upon subsequent emitter means signal changes.   
     
     
       5. In a wire matrix printer having a print head which moves bidirectionally across a record medium, said print head including a plurality of actuatable print wires which can be actuated as said print head moves across said medium, each wire, upon actuation, striking ribbon means against said medium, whereby a mask is printed on said medium, said wire matrix printer further having printer emitter means across which said print head moves for providing a a sequence of signals manifesting each successive incremental movement of said print head, said printer emitter signal sequence being different for different directions that said printer moves, said wire matrix printer further having an improvement of control means comprising: programmable processor means having an interrupt input, and   decoding logic means responsive to said printer emitter signals and to enabling signals provided by said processor means for providing an interrupt signal to said interrupt input each time an incremental movement of said print head is manifested by said emitter signals;   said processor means being programmed in response to said decoding logic means signal being applied to said interrupt input thereof to provide actuation signals causing the selective actuation of said wires, said actuation signals being provided a desired time after the provision of said decoding logic means signals, said processor means further providing said enabling signals to said decoding logic means in accordance with the then occurring printer emitter signal sequence.   
     
     
       6. The invention according to claim 5 wherein said control means further comprises means for determining said desired time. 
     
     
       7. The invention according to claim 6 wherein said enabling signal is provided having a state related to the then existing value of said print emitter signals after said interrupt signal is applied to said interrupt input. 
     
     
       8. The invention according to claim 5 wherein said control means further comprises means for determining said desired time. 
     
     
       9. The invention according to claim 8 wherein said means for determining said desired time includes a programmable timer which is programmed to provide a signal to a second interrupt input of said processor means said desired time after being programmed. 
     
     
       10. The invention according to claim 9 wherein said programmable timer is programmed to provide a signal to said second interrupt input at a plurality of times after being programmed. 
     
     
       11. The invention according to claim 9 wherein said programmable timer is programmed by said processor means to provide a signal to said second interrupt input at a plurality of times following said interrupt signal being applied to said first mentioned interrupt input. 
     
     
       12. The invention according to claim 11: wherein said print head is moved across said medium by a controllable motor, and   wherein said programmable timer is programmed to control said motor.   
     
     
       13. The invention according to claim 11 wherein said enabling signal is provided having a state related to the then existing value of said print emitter signals after said interrupt signal is applied to said interrupt input. 
     
     
       14. In a wire matrix printer having a print head which moves across a record medium, said print head including a plurality of actuatable print wires which can be actuated as said print head moves across said medium, each wire, upon actuation, striking ribbon means against said medium, whereby a mark is printed on said medium, said wire matrix printer further having printer emitter means across which said print head moves for providing a signal manifesting each successive incremental movement of said print head, said wire matrix printer further having an improvement of control means comprising; programmable processor means having an interrupt input, and   decoding logic means responsive to said printer emitter signals for providing a signal to said interrupt input each time an incremental movement of said print head is manifested by said emitter signals;   said processor means being programmed in response to said decoding logic means signal being applied to said interrupt input thereof to provide actuation signals causing the selective actuation of said wires, said actuation signals being provided a desired time after the provision of said decoding logic means signal;   wherein said control means further comprises means for measuring said desired time;   wherein said means for measuring said desired time includes a programmable timer which is programmed to provide a signal to a second interrupt input of said processor means said desired time after being programmed;   wherein said programmable timer is programmed by said processor means to provide a signal to said second interrupt input at a plurality of times following said decoding logic means signal being applied to said first mentioned interrupt input;   wherein said decoding means logic further responds to a control signal provided by said processor means, said control signal having a state related to the value of said print emitter signals after said decoding means logic signal is applied to said interrupt input; and   wherein said decoding means logic includes exclusive OR means responsive to said print emitter means signal and to said control signal; said first interrupt signal being provided by said exclusive OR means whenever said print emitter means signal manifests an incremental movement of said print head, said processor means responding to said first interrupt signal to cause a change in said control signal so that subsequent interrupt signals are provided by said exclusive OR means for subsequent print emitter means signals.   
     
     
       15. Control means for a printer having a matrix print head which moves across a record medium, said print head printing information on said medium by selective operation of the print elements of said print head, said control means comprising: means for providing positioning signals at periodic interim positions as said print head moves across said medium;   programmable timer means which provides a signal after the expiration of a time programmed therein; and   processor means responsive to said positioning signals for programming said timer means to provide signals after a given time to selectively cause the operation of said print elements, said timer means signal being coupled to interrupt said processor means, said processor means providing signals to cause said print elements to be operated in response to said timer means signal.   
     
     
       16. The invention according to claim 15: wherein said print head is capable of moving across said medium in either one of two directions; and   wherein timer means is programmed so that said print elements are operated to print at substantially the same point on said medium regardless of the direction of movement of said print head.   
     
     
       17. The invention according to claim 16 wherein said printer is a wire matrix printer and said operated print elements are actuated print wires. 
     
     
       18. The invention according to claim 16 wherein said printer is a wire matrix printer and said operated print elements are actuated print wires. 
     
     
       19. The invention according to claim 16 wherein said timer means is further programmed by said processor means to control the velocity at which said print head moves. 
     
     
       20. The invention according to claim 19 wherein said print elements are capable of being operated at a plurality of desired positions between each interim position; and   wherein said timer means includes a portion for each of said plurality of desired positions, each of said timer means portions being individually programmed by said processor means upon said processor means responding to said each positioning signals.   
     
     
       21. The invention according to claim 20 wherein said timer means includes an additional portion for being programmed to control the velocity of said print head. 
     
     
       22. The invention according to claim 15 wherein said timer means is further programmed by said processor means to control the velocity at which said print head moves. 
     
     
       23. In a wire matrix printer having a print head which moves across a record medium, said print head including a plurality of actuatable print wires which can be actuated as said print head moves across said medium, each wire, upon actuation, striking ribbon means against said medium, whereby a mark is printed on said medium, said wire matrix printer further having printer emitter means across which said print head moves for providing a signal manifesting each successive incremental movement of said print head, said wire matrix printer further having an improvement of control means comprising: programmable processor means having an interrupt input; and   programmable timer means responsive to programming signals provided thereto from said processor means for being set to provide an interrupt signal to said interrupt input a desired time after being programmed;   said processor means being programmed to provide actuation signals in response to said interrupt signal, said actuation signals causing the selective actuation of said wires.   
     
     
       24. The invention according to claim 23 wherein said processor means responds to said printer emitter signals by programming said timer means. 
     
     
       25. The invention according to claim 24 wherein said timer means responds to programming signals from said processor means for being set to provide a plurality of interrupt signals to said interrupt input at a plurality of desired times after being programmed. 
     
     
       26. The invention according to claim 25 wherein said timer means further is programmable to control the movement of said print head. 
     
     
       27. The invention according to claim 26 wherein said print head moves under the control of a motor; and wherein said timer means includes a plurality of individually programmable portions, one of which is dedicated to being programmed as an oscillator for controlling said motor and others of which are dedicated to being programmed to provide a signal a certain programmed time being programmed for interrupting said processor means.   
     
     
       28. The invention according to claim 24 wherein said processor means is interrupted by said print emitter signals to program said timer means.